local mmi, mma = math.min, math.max
local n, k = io.read("*n", "*n", "*l")
local w, c = {}, {}
for i = 1, n do
  local s = io.read()
  local wi, ci = s:match("(%w+) (%d+)")
  w[i] = wi
  c[i] = tonumber(ci)
end
local t = {}
local edge = {}
for i = 1, k * 3 + 1 do
  edge[i] = {}
  t[i] = -1
end
for i_n = 1, n do
  for j = 1, k * 3 do
    local step = 0
    local need_j = mma(0, k + 1 - j)
    local need_o = mma(0, mmi(k, 2 * k + 1 - j))
    local need_i = mmi(k, 3 * k + 1 - j)
    for i_w = 1, #w[i_n] do
      local ww = w[i_n]:sub(i_w, i_w)
      if 0 < need_j then
        if ww == "J" then
          step = step + 1
          need_j = need_j - 1
        end
      elseif 0 < need_o then
        if ww == "O" then
          step = step + 1
          need_o = need_o - 1
        end
      elseif 0 < need_i then
        if ww == "I" then
          step = step + 1
          need_i = need_i - 1
        end
      end
    end--i_w
    if 0 < step then
      if edge[j][j + step] then
        edge[j][j + step] = mmi(edge[j][j + step], c[i_n])
      else
        edge[j][j + step] = c[i_n]
      end
    end
  end--j
end--i_n
t[1] = 0
for i = 1, 3 * k do
  local srccost = t[i]
  if 0 <= srccost then
    for dst, cost in pairs(edge[i]) do
      if t[dst] == -1 then
        t[dst] = srccost + cost
      else
        t[dst] = mmi(t[dst], srccost + cost)
      end
    end
  end
end
print(t[3 * k + 1])